1. Field of the Invention
The present invention pertains to an air distribution blower housing that has an adjustable restriction in the interior of the blower housing. The adjustable restriction has the configuration of a rectangular plate. One edge of the plate is connected by a pivoting connection to a wall of the blower housing in the air flow path from the blower housing. The plate can be pivoted about the pivot connection through a plurality of adjusted angular positions of the plate in the air flow path. In each adjusted position of the plate, the length of the plate extends from the pivot connection in the air flow direction. A sliding connection is provided between the plate and at least one side wall of the blower housing. The sliding connection selectively holds the plate in its adjusted angular position and also provides a visual indication on the exterior of the blower housing of the adjusted angular position of the plate inside the blower housing.
2. Description of the Related Art
Air condition systems are currently designed with an adjustable capacity. This adjustable capacity enables manufacturers of the systems, distributors of the systems, or contractors that install the systems to meet the different requirements of a relatively wide range of HVAC installations used in a relatively wide range of building constructions. These conditioning systems can be operated in a wide range of cooling capacities by employing a cooling module having a condensing unit of the required capacity for the particular building construction, and by adjusting the volume rate of air flow through the system.
A typical air conditioning system that employs the prior art restrictor plate to adjusts the air flow distribution from the system is disclosed in the U.S. Patent of Dieckmann et al. U.S. Pat. No. 5,277,036, the disclosure of which is incorporated herein by reference. An air conditioning system of this type typically includes a heating module, a cooling coil or module, and a blower.
The cooling module, the heating module, and the blower are typically assembled so that operation of the blower draws an air flow through the system. The drawn air flow direction is through the heating module, then through the cooling module, and then through the blower. This sequence of the air flow direction is desirable because if the cooling coil of the cooling module produces an air flow at below freezing temperature, then the heating coil of the heating module will not freeze and potentially burst.
The heating coil assembly functions as a heat exchanger that heats the air drawn through the coils by operation of the blower. The coils of the assembly typically communicate with a source of hot water and channel the hot water through the coils. The hot water heats the air drawn through the heating coil assembly by the operation of the blower.
The air flow volume of the air drawn through the system by operation of the blower is typically adjusted according to the cooling capacity of the condensing unit of the cooling coil of the system. The air flow volume rate is adjusted to achieve a constant air flow volume rate per unit of cooling capacity, for example, 200 cubic feet per minute (CFM) per ton.
In the prior art, a variable restrictor plate has been employed to fine tune the air flow to reduce the noise from the register if the total air flow is more than the minimum required. If noise is not an issue, then having more air flow than the minimum is better. Thus, most of the time the restrictor plate will be in the fully opened position. The prior art adjustable restrictor plate is slidably mounted across a discharge opening of a duct or a discharge opening of a blower housing. The plate is positioned substantially perpendicular to the direction of air flow. Movement of the plate across the discharge opening varies the area of the opening according to the air flow volume rate required for the cooling capacity desired of the system. These prior art adjustable restrictor plates have been seen to be disadvantaged in that the adjustable positioning of the plate across the discharge opening disrupts a smooth flow of air through the discharge opening. This disruption in the smooth flow of air through the discharge opening has been observed to negatively affect the efficiency of the air conditioning system blower. In addition, the adjustable positioning of the restrictor plate across the air discharge opening has the negative effect of generating noise due to the air flow around the restrictor plate.